Device for amplifying the effect of sound-waves.



w. H. COTTON.

DEVICE FOR AMPLIFYING THE EFFECT 0F SOUND WAVES.

APPLICATION FILED DEC. Il. l9ll. 'RENEWED MAR. 22, |916.

1,200,815. Patented Ott. 10,1916. *i

muren stradine rarnnr orrron. i

WALTER H. CO'ITGINT, 0F CHICAGO, ILLINOIS, ASSIGNOR, BY DIRECT AND MESNE i ASSIGNMENTS, TO FREDERICK A. WATKINS, F CHICAGO, ILLINOIS.

DEVICE FOR AMPLIFYING THE EFFECT 0F SGUNIJl-WAVES.

Lacoste.

v.Sqieciicaton of Letters Patent.

Patented oct. 1o', 1916.

Application filed December 1.1, 1911, Serial No. 664,958. Renewed March 22, 1916. Serial'No. 85,972.

thereon, which form a part of this specification. Y, y

This invention relates to a device for amplifying the eiect of sound waves for ythe purpose of intensifying or enlarging the vol- .ume of sound produced by projection of soundwaves against a diaphragm.

A device embodying Mn iy'u'ivention embraces a member arranged inthe path oi the sound waves, with the side .thereof which is directed away from the source producing' the sound waveshaving the form 'of a concave surface of substantially parabolic contour; the arrangement, being such that the.sound waves between the said concave surface o1n the member and a diaphragm against which the sound waves are projected are directed or reflected in straight or substantially straight lines upon the diaphragm so as to thereby not only secure the impressinent of a larger number of the sound waves upon the dian phragm but also to prevent the escape or dissipation of the sound waves.

My device may be applied in any situation for amplifying and conserving lthe eli'ects of sound waves. I have herein shown it as applied to a telephone receiver in Which the use of the concave side of the'said member faces outwardly or in opposition to the human ear drum, when the receiver is placed to the ear.

In the use of the device in a telephone trans-v mitter said member may be arranged with the concave or parabolically curved side toward the diaphragm of the transmitter, such for instance, as shown in my prior application for U. S. Letters .Patent No. 660,241, filed November 14th, 1911. In other uses of the device, among which `may be mentioned, for instance, its application for intensifying sound waves projected from a phonograph, the device may be arranged in the same general relation to the direction of movement of phragm of the instrument.

The invention consists in the matters here? inafter set forth and more particularly pointed out in the appended claims.

In the drawings Figure 1 is a sideelevation of a telephone receiver, partlyin section, showing my improvements applied thereto, the section being on the lineA 1-1 of Fig; 2. Fig. 2 is an inslde end elevation of the ear prece removed from the body of the' receiver. Fig. 3 is an outside end elevation of said ear plece. Fig. 4c is a partial elevation and partial section of a modification. As shown in the drawings 10 designates the usual hollow rubber or like non-conductingloody of a telephone receiver having at its rear end the usual binding posts y'11, l2 for connection with the wires ofthe cord 13. The other end or head 14 of the body is provided with' an exterior s crewthread to re; ceive the `ear piece, designated in lFigs. 1, 2 and 3 by lo', said ear piece having an annular rim portion 1G which is interlorly vscrewthreaded vand which ts'over and engages the exterior screw-threa`d of the head portion. yThe said ear piece is providedwith an interior annular shoulder 17 between which and the margin of the hollow head is conne'd the receiver. diaphragm 18.

Arranged within the hollow ear piece 15, and made integral therewith, asV shown in Fig. 1, is a concavo-convex shell 20, the concave side of which faces inwardly, and between which and the diaphragmv is'formed an intermediate chamber 19. Said shell .is provided centrally with an opening 21, and around said opening with an annular, inwardly extending lip 22. Arranged on the concave side of saidshell and axially coinciding with the opening 21 thereof -is a con-' cavo-convex member 24, the concave side of which is directed outwardly toward said opening 21, and the pointed or convex side ofy which is directed' inwardly toward thediaalmost complete annular space or vslot '.25 y

the chamber 19 to the other side of the ear piece. The said member may be attached tov the shell 20 in any suitable manner that will the passage of the sound vwaves.through the annular space 25. As herein shown the 'said` member is made an integral part of Said through which the sound waves 'pass from i interfere to as small extentas possible with I member 24.

shell, itv being connected to the Ishell by the integral fin-like arms 26 arranged in planes radial to the axis of the opening 2 1 and the In vthe use of the device sound waves pass from the chamber 19 -throllgh the' annular 4opening and into the space betweenthe member 24 `and the ear drum of the personI to increasethe volume ofthe reproduced with an annu1ar,'inwardl extending vlip 36,-

sounds. member has the effect of concentrating or conserving the sound waves and .prevents dissipation thereof. This latter effect is especially noticeable 'in the use of the device in sound transmitters. With the use of this device, therefore, comparatively feeble sounds transmitted therethrough are reproduced on the ear drum with a ma fied edect. Also the device has `the e ect to make it possible to transmit andreproduce sound waves of practicalvolume at the-initial or producing point over longer distances and reproducing them in "ample volume at the receiving stationl than with devices for this purpose heretofore in use.

As shown in Fig. 4, I have provided a modification designed to closely simulate the standard ear piece now in use.' In this construction 28 *designates the standard Arubber ear piece` having the usual central opening 29 and provided with an internally screw-threaded rim 30. 31 designates. a coupling sleeve which yis provided vat its inner .end with an internal screw-thread to engage the external screw-thread `,olf the head `14, and is provided at its outer end with an external screw-thread to engage' the internal screw-thread ofthe rim-3U of the ear piece. The said coupling sleeve is also provided rwith an internal, annular shou1 der 32 between which and the outer margin of the hollow head is clamped o`r confined the receiver i diaphragm 18. In this con-- struction the hollow shell 34 (correspond` ingv to the shell 2O of thepreviously dei,

scribed construction) is made apart integral with the coupling sleeve 21. Said shell 34 is formedl with a 4central opening 35.

which axially coincides with the central opening 29 of' the-ear piece, and is formed corresponding withv the ip 22 of the previously described construction. 37 designates av concavo-convex member interposed between said opening 29 and the diaphra 18,\\`vith its concave side dircctedoutwar y and formed on-a substantially parabolic curvature, and with its inner or convex side i s r Moreover, the .presence of said` -chamber between the shell 34 ,and diaphragm 18` pass to the outer side of the .member 37. Said member 37, as herein shown, is made an integral part with the shell 34 and is connected thereto by the thin o1' fin-like webs or arms 40. l

The use or operation of thislatter described modification is the same as the construction 'first described. By reason of the employment of the coupling sleeve, having an interior screw-thread-at one end to en-I gage the exterior screw-thread of the head, and having the exterior screw-thread at its other end to engage the interior screwthread of the ear piece, I Yam' enabled'to provide a construction which differs lbut little in its exterior contour from the ordinary` or standard receiver. e

It will be obvious that my improvements may be`-otherwise applied to produce the results set forth and that the specific construction thereof may be considerably varied without departure from thespirit of the invention.

i I'claim as my invention 1. A device for concentrating and amplifying the effect of sound waves, comprlsing a concavo-convex member arranged in the path of the sound waves and wholly within a chamber, the walls of which constitute the bbundaries of the path, with the concave jside of the member facing away from the source producing the sound waves and asV toward a restricted opening in the wall of said chamber, and of substantiallyfthe di-4 .ameter of said restricted opening, the concave side of the member having a parabolic contour. 4

2. In a device for the purpose set forth, the combination withl a conduit for sound waves, a diaphragm extending thereacross, a shell, between which andthe diaphragm is formed 'il chamber,.said shell being provided opposite to the diaphragm with a restricted opening, and a concavo-convex inemberlf'between the shell and the diahragm and wholly within the shell, and.

a ranged with its c vex side facing toward but outof contact ith the diaphragm and with its/concave side facing toward said opening and away from the .source prdducing the 'sound' waves,there being a passage between saidmember and the shell wall.

` `3. A receiver-comprisin o en at one end,`a diap ragm extending across the' open end of the body, a ear piece fixed to the body and formed wit an a hollow body apertured shell or wall to provide between i the same and the diaphragm a' chamber,

and a member arranged betfween said shell ing and provided with an internal shoulder,

between which and saidopen end of the body the diaphragm is confined, and a meinber arranged between said diaphragmv and I wall and having a concave surface facing the aperture of said earpiece and spaced a distance from said ear piece.

5. A receiver compris'rng a hollow body having an open end, a diaphragm extendn ing across said piece having a central opening, a coupling sleeve for removably fixing the ear piece to the body and constructed to form a chamber between same and said diaphragm, and a member in said chamber having a concave surface presented toward the aperture of open end 4of the body, an ear between t e saine land the ear lpiece.

l 6. A. receiver comprising a hollow body having an open end provided with an ex terior screw-thread, a centrally Aapertured ear piece provided with an interior screwthread, a coupling sleeve having at its ends interior and exterior screw-threads, respectively, to engage the @few-threads of said body and ear piece, a diaphragm extending across the open end oi' the hollow body, and a member between central aperture o the ear piece and 'spaced from the eer piece, and formed on the side facing -the aperture with a parabolic contour.

in testimony'that l claim the foregoing as myv invention l aiiix my signature in the presence of two witnesses, this 24th day of November, A.. D., 19M.

waarna n. oo'r'ioii.

Witnesses W. L. HALL, G. E. Bowman.

35 the diaphragm and the 

